Stabilizing cell phone video using inertial measurement sensors. In:

Abstract We present a system that rectifies and stabilizes video sequences on mobile devices with rolling-shutter cameras. The system corrects for rolling-shutter distortions using measurements from accelerometer and gyroscope sensors, and a 3D rotational distortion model. In order to obtain a stabilized video, and at the same time keep most content in view, we propose an adaptive low-pass filter algorithm to obtain the output camera trajectory. The accuracy of the orientation estimates has been evaluated experimentally using ground truth data from a motion capture system. We have conducted a user study, where the output from our system, implemented in iOS, has been compared to that of three other applications, as well as to the uncorrected video. The study shows that users prefer our sensor-based system

A model of access combining triage with initial management reduced waiting time for community outpatient services: a stepped wedge cluster randomised controlled trial

BACKGROUND: Long waiting times are associated with public community outpatient health services. This trial aimed to determine if a new model of care based on evidence-based strategies that improved patient flow in two small pilot trials could be used to reduce waiting time across a variety of services. The key principle of the Specific Timely Appointments for Triage (STAT) model is that patients are booked directly into protected assessment appointments and triage is combined with initial management as an alternative to a waiting list and triage system. METHODS: A stepped wedge cluster randomised controlled trial was conducted between October 2015 and March 2017, involving 3116 patients at eight sites across a major Australian metropolitan health network. RESULTS: The intervention reduced waiting time to first appointment by 33.8% (IRR = 0.663, 95% CI 0.516 to 0.852, P = 0.001). Median waiting time decreased from a median of 42 days (IQR 19 to 86) in the control period to a median of 24 days (IQR 13 to 48) in the intervention period. A substantial reduction in variability was also noted. The model did not impact on most secondary outcomes, including time to second appointment, likelihood of discharge by 12 weeks and number of appointments provided, but was associated with a small increase in the rate of missed appointments. CONCLUSIONS: Broad-scale implementation of a model of access and triage that combined triage with initial management and actively managed the relationship between supply and demand achieved substantial reductions in waiting time without adversely impacting on other aspects of care. The reductions in waiting time are likely to have been driven, primarily, by substantial reductions for those patients previously considered low priority. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12615001016527 registration date: 29/09/2015

Gyrobaserad videostabilisering och korrektion för rullande slutare

Most mobile video-recording devices of today, e.g. cell phones and music players, make use of a rolling shutter camera. A rolling shutter camera captures video by recording every frame line-by-line from top to bottom of the image, leading to image distortions in situations where either the device or the target is moving. Recording video by hand also leads to visible frame-to-frame jitter. In this thesis, methods to decrease distortion caused by the motion of a video-recording device with a rolling shutter camera are presented. The methods are based on estimating the orientation of the camera from gyroscope and accelerometer measurements. The algorithms are implemented on the iPod Touch 4, and the resulting videos are compared to those of competing stabilization software, both commercial and free, in a series of blind experiments. The results from this user study shows that the methods presented in the thesis perform equal to or better than the others.Mobiltelefoner, mp3-spelare och andra bärbara enheter som kan spela in film har ofta en kamera med rullande slutare. En sådan kamera fångar varje bild rad för rad, från topp till botten. Detta resulterar i distortion i bilden om antingen enheten eller objekt i bilden rör sig. Att filma för hand introducerar också skakighet i filmen. I det här examensarbetet presenteras metoder för att minska den distortion som uppstår till följd av att en enhet med rullande slutare förflyttas under inspelning av en film. Metoderna bygger på estimering av kamerans orientering, utgående från mätdata från gyroskop och accelerometer. Algoritmerna har implementerats på en iPod Touch 4 och de resulterande filmerna har jämförts med de från konkurrerande program i en serie blindtester. Resultaten från denna undersökning visar att metoderna som presenteras i examensarbetet är lika bra eller bättre än de övriga